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arctics2's avatar
arctics2
Level 5
12 years ago
Solved

Buffer Settings for Duplication to LTO 5 Tape

We're using a Netbackup 5230 Appliance connected via 8Gb fibre to an HP MSL 8096 LTO 5 tape library with 4 drives.  I've read many posts recommending leaving the buffer size as default:

SIZE_DATA_BUFFERS                                 : 262144 (Default)
SIZE_DATA_BUFFERS_DISK                        : 262144 (Default)
SIZE_DATA_BUFFERS_FT                            : 262144 (Default)
 
This is how they are currently set, and when monitoring backups to disk, I see the following in the log:
 
01/29/2014 19:49:09 - Info bptm (pid=3752) using 262144 data buffer size
01/29/2014 19:49:09 - Info bptm (pid=3752) using 30 data buffers
 
Which is expected, however, when duplicating to tape, the logs indicate the following:
 
01/31/2014 17:00:15 - Info bptm (pid=30607) using 65536 data buffer size
01/31/2014 17:00:15 - Info bptm (pid=30607) using 30 data buffers
 
Can someone clarify why it would be set this way and is this as expected?
 
Thanks

 

  • If you have not modified the default buffer sizes you will need to do so - but as the one can affect the other make sure you do both

    From the CLISH of the appliance follow this process:

    Go to the Settings menu and then type:

    NetBackup DataBuffers Number Show
    NetBackup DataBuffers Size Show

    to see what they currently are. To change them use:

    NetBackup DataBuffers Number Disk 64
    NetBackup DataBuffers Number Tape 64
    NetBackup DataBuffers Size  Tape 262144
    NetBackup DataBuffers Size  Disk 1048576

    The disk setting is up to you but generally works well - as do the numbers used above

    Hope this helps